#include<iostream>
#include<set>
#include<string>
using namespace std;
int main(){
	set<string> country;
	country.insert("China");
	country.insert("America");
	country.insert("France");
	for(set<string>::iterator it=country.begin();it!=country.end();it++){
		cout << *it << " ";
	}
	cout << endl;
	country.erase("America");
	country.erase("England");
	if(country.count("China")){
		cout << "China in country" << endl;
	}
	return 0;
}
